Staging, grading and related histopathological techniques in local therapy of rectal tumours.

Today, local therapy is an established alternative to radical resection for the treatment of rectal tumours. Selection of the operative technique requires an exact perioperative estimation of risks, with both clinical and histopathological examination. Of crucial importance in making a decision to perform a local resection is exact and meticulous histopathological preparation of the tissue. The most important criterion is the estimation of risk of lymph node metastases. This risk is assessed on the basis of the depth of invasion of the tumour, the histological grade of differentiation and the presence or absence of invasion of lymphatic vessels.